Lamp base



FIG. 1 is a perspective view of the lamp base showing my new design; and,

FIG. 2 is a front elevation view of the lamp base of FIG. 1.

Features shown in broken lines are shown for environment only and do not form a part of the design claimed. The bottom and top of the lamp base of FIGS. 1 and 2 are without adornment, are not a part of my ornamental design and are not separately shown in the drawings. The left, right and rear elevations are identical to FIG. 2, and so are not separately shown. 

The ornamental design for a lamp base, as shown and described. 